Filter structure



Jan. 16, 1962 A. R. GETZIN FILTER STRUCTURE Filed Jan. 8, 1958 FIGJ L22 INVENTOR.

ALLAN R. GETZIN QM QM ATTORNEY United States PatetIt OI 3,016,602 FILTER STRUEIURE Allan R. Getzin, .leffersontown, ity, assignor to American Air Filter Company, Inc, Louisville, Ky, a corporation of Delaware Filed .lan. 8, 1958, Ser. No. 707,793 4 Claims. (Cl. 29-190) The present invention relates to fluid filters and, more particularly, the present invention relates to an improved frame construction for holding fluid filters.

In the industrial installation of fluid filters such as those of the viscous impingement type which include filter pads of fibrous glass material or wire mesh material usually encased in cardboard or fiber-board frames, it has been found to be frequently advantageous to mount such filters further in frames of sturdy construction before they are installed for actual operational use.

The present invention provides a structural arrangement for such filter frames so that the frames can be both light in weight and sturdy in construction and yet can be produced readily and economically at a manufacturing plant, shipped in a compact, unassembled fashion, and then assembled at the point of use in a straight forward and efficient manner with a minimum of effort and skill.

Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth hereinafter.

More particularly, the present invention provides a knock-down filter frame structure for holding a fluid filter comprising: a pair of filter frame members, each member including a plurality of end-to-end connected side panels, the side panels of each member being divided from each other by one of a first set of transverse score lines in order to facilitate the bending of one side panel with respect to its adjacent panel, a connecting panel extending from one of the ends of the end-to-end side panels of each frame member, the connecting panel being divided from the side panel from which it extends by a transverse score line, a filter retaining panel depending from a corresponding side of each one of the end-to-end side panels, each of the filter retaining panels being di vided from the side panel from which it depends by one of a second set of score lines transverse to the first set of score lines in order to facilitate the bending of each of the filter retaining panels at a 90 angle with respect to the side panel from which it depends, a first means to join together adjacent ends of adjacent filter retaining panels of each frame member when such retaining panels have been bent at 90 to their respective side panels, a second means to join together the free ends of the filter retaining panels of one of the frame members with the free ends of the filter retaining panels of the other frame member, and a third means to join each of the connecting panels of one frame member to a side panel of the other frame member.

It is to be understood that various changes can be made by one skilled in the art in the arrangement, form and construction of the several parts of the structure disclosed herein without departing from the scope or spirit of this invention.

Referring to the drawings which disclose one advantageous embodiment of the present invention:

FIGURE 1 is a broken plan view of one of the blanks used in assembling the inventive filter frame structure;

FIGURE 2 is a perspective view of one corner of the filter frame structure of FIGURE 1, disclosing an early stage of the frame assembly with the tongue of one retaining panel ready for insertion into a slot positioned in a tab portion of an adjacent retaining panel;

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FIGURE 3 is a perspective view of the same corner of the filter frame structure of FIGURE 2, disclosing a further stage of the assembly with one side panel bent at an angle with respect to the adjacent side panel and the tongue of the retaining panel partially inserted into the slot in the tab portion of the other retaining panel;

FIGURE 4 is another perspective view of the same corner of the frame structure disclosed in FIGURES 2 and 3, disclosing the tongue of the one retaining panel fully inserted into the slot in the tab portion of the other retaining panel and a screwdriver inserted beneath the tongue to bend it away from the assembly;

FIGURE 5 is still another perspective view of the same corner of the frame structure disclosed in FIGURES 24 inclusive, disclosing a pair of pliers in engagement with the tongue of one retaining panel and the tab portion of the other panel prior to bending the tongue and tab into finally assembled position; and,

FIGURE 6 is a reduced perspective view of the overall filter frame structure after it has been fully assembled and ready to receive a filter medium encased in a cardboard frame.

Referring to FIGURE 1 of the drawings, a blank 2 is disclosed from which the filter frame structure can be assembled. Blank 2 can be made from any one of a number of sturdy, thin, lightweight metals, and, advantageously, a corrosion resistant zinc grip type metal can be used. The blank, which can be stamped to desired configuration by any one of a number of well known metal stamping machines, is arranged to include the end-to-end connected side panels 4- which are divided from each other by a transverse perforated score line 6. Pending from a corresponding side of each of the side panels 4 is a filter retaining panel 8, each of the filter retaining panels 8 being divided, in turn, from its respective side panel 4 by one of a second set of score lines 12. Lines 12 extend along the blank 2 from one extremity of the blank to the other in transverse relationship to score line 6.

Each of the filter retaining panels 8 has integral therewith at a corresponding corner extremity thereof a tongue portion 14-. As will be observed, each tongue portion 14 is stamped so as to be offset at 16 from the plane which determines its filter retaining panel 8. In addition, a score line 1% is provided at each tongue corner of the retaining panels 3 to permit ready bending of each tongue 14.

Positioned at the corresponding opposite corner extremity from the tongue corner of each filter retaining panel 8 is a tab portion 22. Each tab portion is divided from its filter retaining panel 5 by a score line 24 and each tab portion has disposed therein and spaced from the score line 24, a slot 26. It is to be noted that each slot 26 is positioned at such an angle as to be able to receive a tongue A of an adjacent retaining panel 8 when the frame structure is assembled (as is described hereinafter).

In the drawings, blank 2 is disclosed as having two side panels 4 bendable about score line 6. Accordingly, to form the rectangular frame as disclosed in FIGURE 6, a second blank including side panels and filter retaining panels similar to blank 2 of FIGURE 1 would be required. In this connection, it is to be understood that instead of two separate blanks a continuous blank having four side panels and four filter retaining panels which incorporate the features of the two separate blanks could also be used in place of the two separate blanks. And, it is further to be understood, that the number of side and retaining panels can be varied in accordance with the shape and number of sides of the filter media which is to be used with the filter frame.

In order to connect the ends of side panels 4 together,

regardless of whether a single continuous blank or a number of separate blanks are used to form the frame, a connecting panel 32 is provided at one end of the endto-end connected side panels 4. This connecting panel 32 is divided from its side panel 4 by transverse score line 34 which extends across the blank in a direction normal to transverse score lines 12 and parallel with transverse score line 6. The upper portion of connecting panel 32 is provided with a slot 38 and, in this connection, the opposite end of the end-to-end connected side panels is slit to provide a tongue 42. As will be seen hereinafter, tongue 42 of side panel 4 is engageable with slot 38 of a connecting panel 32 when the frame is assembled.

In assembling blank 2 to form a filter frame, the retaining panels 8 are bent about the score lines 12 at a 90 angle so as to be perpendicular to the side panels 4 (FIG- URE 2). When this has been accomplished, the tab portion 22 of one retaining panel 8 is bent downwardly so that the slot 26 included therein is ready to receive a tongue 14 of an adjacent retaining panel 8. At this point (FIGURE 3), side panels 4 are bent about the score line 6 so that the tongue 14 engages in slot 26 of tab portion 22. Referring to FIGURE 4 of the drawings, when tongue 14 has been inserted fully into its slot 26, a screwdriver can be used to bend the tongue 14 away from the frame assembly. It is then only necessary to grip tongue 14, along with its tab portion 22, with a pliers and bend them away from the direction in which the tongue has been inserted and into final position (FIG- URE It will be noted that the several corners of the frame structure can be assembled in a manner as hereinabove described and, if several separate blanks are used, such separate blanks can be assembled to each other in a similar manner. It also will be noted that in assembling that corner which includes connecting panel 32, panel 32 is bent at a 90 angle about its score line 34 so as to overlap the face of an end side panel 4 having a tongue 42. The tongue 42 then is inserted through slot 38 of connecting panel 32 and bent downwardly to fasten the side panels firmly and thus complete the asesmbled frame 45 (FIG- URE 6).

Once frame 45 has been assembled properly, the filter medium assembly 46 can be inserted therein. As is known in the art, the assembly 46 includes a filter medium pad 47 which is surrounded by a fiberboard frame 48 and positioned between perforated metal grids 50. Once assembly 46 is inserted in frame 45, it can be held in frame 45 by means of pivotally mounted, helical hold-down springs 52, these helical hold-down springs being mounted in slits 53 provided along the inner sides of the assembled frame 45.

The invention claimed is:

1. A filter frame blank for a knock-down filter frame which when assembled serves to hold a fluid filter comprising: a plurality of end-to-end connected side panels, said side panels being divided from each other by a first set of transverse score lines, a filter retaining panel depending from a corresponding side of each of said side panels, said filter retaining panels each being divided from its respective side panel by one of a second set of score lines transverse to said first set of score lines, each of said filter retaining panels having integral therewith at one corresponding extremity thereof atongue portion and having positioned at an opposite corresponding extremity thereof a slotted tab portion to receive the tongue portion of an adjacent filter retaining panel, a connecting panel extending from one of the ends of said end-to-end connected side panels, said connecting panel being divided from said side panel from which it extends by a transverse score line, and means to connect said connecting panel to another side panel in forming said filter frame assembly.

2. The filter frame blank of claim 1, wherein said means to connect said connecting panel to said side panel includes a tongue and slot arrangement in said connecting and side panels.

3. A knock-down filter frame structure to hold a fluid filter comprising: a pair of connected filter frame members, each member including a plurality of end-to-end connected side panels, said side panels of each frame member being divided from each other by'a first set of transverse score lines about which of one side panel is bent at a suitably preselected angle with respect to its adjacent panel, a connecting panel extending from one of the ends of said end-to-end connected side panels of each frame member, said connecting panel being divided from said side panel from which it extends by a transverse score line and being bent about such transverse score line at a suitably preselected angle, a filter retaining panel depending from a corresponding side of each of said side panels, each of said filter retaining panels being divided from its respective side panel by one of a second set of score lines transverse to said first set of score lines and bent at a angle to the side panel from which it depends about such score line, a first means to join together adjacent ends of adjacent filter retaining panels of each frame member when said panels have been bent at 90 to their side panels, a second means to join together the free ends of the filter retaining panels of one of said frame members with the free ends of the filter retaining panels of the other of said frame members, and a third means to join each of the connecting panels of one frame member to a side panel of the other frame member.

4. The filter frame structure of claim 3, wherein each of said first, second and third means includes an engaged tongue and slot arrangement.

References Cited in the file of this patent UNITED STATES PATENTS 820,896 Van Patten May 15, 1906 935,187 Burgess Sept. 28, 1909 1,065,404 St. Helens June 24, 1913 1,299,016 Opitz Apr. 1, 1919 1,450,091 Lard Mar. 27, 1923 2,003,326 Wellman June 4, 1935 2,097,927 Klemp Nov. 2, 1937 2,483,560 Peterson Oct. 4, 1949 2,627,948 Farr Feb. 10, 1953 FOREIGN PATENTS 30,810 Norway June 30, 1920 

